Safety electric switch



@68 Wm l July 4, 1933.

Filed Aug. 2l. 1930 C. A. DE GIERS SAFETY ELECTRIC SWITCH 3She'ets-Sheet 1 a sei 'lll u' IIIII July 4, 1933. c.. A. DE GIERs SAFETYELECTRIC SWITCH Filed Aug. L21. 195o s sheets-sheep 2 I'Illllll-vinI- l,um um",

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SAFETY ELECTRIC SWITCH Filed Aug. 21. 1930 3 Sheets-Sheet 3 EL i! i im lvwemtoz i4 Hwanw@ @Jaw/mw Clo-Tum# Patented July 4, 1933 ETED STATESCLARENCE A. :DE GIERS, OF FOREST HILLS, NEW' YORK, ASSIGNOR T0 THEIIQIIIIDOMI-` ETER, CORPORATION, OF LONG ISLAND CITY, NEW YORK, A.CORPORATION OIF DELAWARE SAFETY ELECTRIC SWITCH Applicationled August21, 1930. Serial No. 476,801.

The principal object of the presentinvention is to Vprovide an electricswitch sodesigned as to be operable in any position and to eliminate alldanger o'sparks passing .therefrom to the surrounding atmosphere orother medium in which the switch may be placed. l l f y ln/locationssuch as hydrogen-filled air ships it is of the utmost importance thatsparks be prevented, and therpresent switch is particularly adapted foruse -under such conditions.

Further and other objects 'of the inven-v tion will be apparent from thespecification and claims, and from the acompanying drawings whichillustrate what is now considered to be the preferred embodiment of theinvention.

Fig. 1 is a cross-section of the device showing the switch in offposition.

Fig. 2 is a view of Fig. 1 from the bottom, with parts broken away.

Fig. 3 is a modification of Fig. 1 with switch in on position.

Fig. 4 is a 'cross-section of a switch similar to Fig. 1 with the.addition of a safety device, the view being taken on the line 4--4 ofFig. 6.

Fig. 5 is a view of Fig.4 from the bottom, with portions partly brokenaway.

Fig. 6 is a view of Fig. 4 from the right end thereof.

Fig. 7 .is a fragmentary view showing a de tail of Fig. 5 in a differentposition.

Fig. 8 is an enlarged detail on the line88 of Fig. 4. Y-

Fig. 9 is a view on the line 9-9 of Fig. 7.

Referring to the drawings, the device comprises a flanged metallic baseplate 20 to which other end anchored to metallic pin 34 on plate 24. Asshown in Fig. 1 the spring is holding blade 28 in non-operative positionagainst stop pin 36 fast in plate 24. When blade 28- is moved upwardlyagainst stop pin 38thel blade passes the center line and is held in thatposition by the same spring.

l/Vhile in raised position blade 28 contacts with conductor button 40,fast on plate 28. To button 40 is soldered an end of conductor wire 42.An end of another conductor wire 44l is fast to pin 34; therefore, whenblade 28 lis ,in contact with button 40 a circuit is closed through wire42, button 40, blade 28, pin 30, spring 32, pin 34, and wire 44.

Wires 42 and 44 are soldered into terminals 46 and 48 respectively, andthe terminals are embedded in a bakelite plug 50 provided with 4aconical face 52 adapted to fit a conical seat Blade 28 is movable bylever 64 having a.

jaw engaging a pin 67 on blade 28, saidA blade being pivoted at 66 onplate 24 and provided with a knob 68. for manual operation. Jaw 65 isformed in insulating material and attached to lever 64 as by rivets 69.

Integral with lever 64 is a disk .or head 7 0, and interconnecting therim of head 70 to arim 72 on base plate 20 is a flexible sylphon 74. Thesylphonis soldered or brazed to rims 7 0 and 72 to form gas-tight jointstherewith. After the switch mechanism is assembledas above described,the air is exhausted from the chamber formed by lhead 70, plate 20 andvsylphon 7 4, through tube 76, which passes .through plate 20 and is'soldered thereto.-

After the air is exhausted the free end of tube 76 is soldered as at 7 8and any excess tubing is coiled around the conduit as at 80. Theflexibility-of sylphon 74 permits ree operation of the switch b knob 68and lever'64 without .breaking t e vacuum within the switch chamber;therefore, there is no op ortunity for sparks generated by the switc tobe communicated tov the medium surrounding the switch chamber.

n the switch illustrated in Figs. 1 and 4, blade 28 is held in on or oitposition by spring 32, Whereas in the modication shown in Fig.l 3, upperstop pin 38 is replaced by a pin 82. so placed that blade 28 cannot passabove the center line; therefore, in that modilication, the switch willremain in on positiononly when held there by the operator, and isimmediately drawn to o position against pin 36 when the operatorreleases knob 68.

In case there is any leakage of surrounding gas or air into the switchchamber there is no danger of flame or spark propagation outwardly fromthe switch chamber until the inside and outside pressures are equalized.Nevertheless it is important that the switch be rendered inoperative andthe operator be informed promptly whenever leakage has occurred, and forthose purposes I provide the devices shownl in Figs. 4 to 9, inclusive,which will now be described. c

In this modification, contact button 40,`instead of being fast onnon-conducting plate 24, is fast on-a bakelite slide 84 movablelongitudinally in a slot in plate 24. Wire 42 is ast to slide 84,therefore when the parts are in normal position as in Fig. 4, and blade28 is up against stop 38, a circuit 1s closed from wire 42 through slide84, button 40, and so on as in F ig. l, tov wire 44. If, however, slide84 is moved to the left suiiciently, button 40 will be out of reach ofblade 28 and no contact,

,and consequently no spark, can be made therebetween.

Slide 84 is movable by a tirst-order lever 86, pivoted at 88 on plate24, engaging pin 90 on the slide, and connected at its upper end by pin92 to horizontal link 94 which passes throughfa clearance hole 96 inbase plate 20 to engage at 98 a disk or head 100, the rim of which isconnected by an axially compressed sylphon 102 to the rim 104 of boss106 on plate 20, thus forming a gas tight chamber in communication withthe switch chamber.

On the outside of head 100 is a jaw member 108 through which a pin 110pivotally engages one end of a lever 112 fulcrumed on pin 114 in the endof stud 116 set into base plate 20. The other end of lever 112 ispivotally connected by pin 118 to an end of plunger 120, on the otherend of which is a disk-122, lettered for instance as in Fig. 9 andnormally concealed from thesight of the operator (as in Fig. 5) by ashutter 124 hinged by spring hinge 125 on plate 20.

Under normal conditions, the switch chamber and sylphon 102 being undervacuum, disk 122 is held tightly against its seat in plate 20 byatmospheric pressure against the outside of head 100 which is suiiicientto overcome any tendency of sylphon 102 to expand axially.

If, however, gas is permitted to enter the structure, to break thevacuum therein,

sylphon 102 will expand axially, moving slide 84 to the left to placebutton 40 beyond reach of blade 28 and moving lplunger 120 also to theleft, whereby shutter 124 and disk 122 assume the positions shown 1nFigs. 7

land 9, thus simultaneously putting the chamber whereby said blade ismoved into orout of contact with said button, and means forautomatically 'preventing said blade and said button from contactingwhen the vacuum in the chamber is broken.

2. In an electric switch, a vacuum chamber, a contact button and acontact blade in said chamber, means for deforming said chamber wherebysaid blade is moved into or out of contact with said button, and meansfor automatically moving said button out of the path of travel of saidblade when the vacuum in said chamber is impaired.

3. In an electric switch, a vacuum chamber, a contact button slidablymounted in said chamber, a blade manually movable into contact 'withsaid button, in combination with means responsive to increase ofpressure within said chamber for sliding said button out of reach ofsaid blade to render the switch inoperative.

4. In an electric switch, a vacuum chamber,

a contact button slidably mounted in said chamber, a blade manuallymovable into contact with said button, in combination with meansresponsive to increase of pressure within said chamber for sliding saidbutton out of reach of said blade to render the switch inoperative, saidmeans bein effective for simultaneously displaying .a s1 al to advisethe o rator that the switch is inoperative.

5. n an electric switch, a vacuum chamber, a contact bltton, and acontact blade in said chamber, an auxiliary vacuum chamber incommuication with said contact chamber, said auxiliary chambercomprising a sylphon having a head, in combination withinstrumentalities interconnecting said head and said button wherebymovement of said head will move v said button to render the switchinoperative.

mentalities interconnecting said head and said button whereby movementof said head will move said button to render the switch inoperative,said. head being movable in response to increase of pressure in saidcontact chamber.

7 In an electric switch, a vacuum chamber, a contact button and acontact blade in said chamber, an auxiliary vacuum chamber incommunication with said contact chamber, said auxiliary chambercomprising a sylphon having a head, a signal normally concealed from theoperator, in combination with instrumentalities interconnecting said heawith said button and with said signal whereby an increase of,` pressurein said contact chamber will render said switch inoperative andsimultaneously display said signal to the operator.

8. In an electric switch, a vacuum chamber comprising a sylphon, astationary support within said sylphon, stationary and movable switchelements mounted on said support, and a switch operating `memberhermetically sealed to the sylphon and pivoted on saidl support forfle'xin the sylphon laterally to operate the movab e switch element andopen elements for opening and closing the switch upon lateral iiexing ofthe sylphon.

10. In an electric switch, a base, a vacuum i chamber comprising asylphon hermetically sealed to the base, a support secured to the baseand projecting into the sylphon, a head on the sylphon, an operatinghandle rigidly connected and hermetically sealed to said head, a pivotalconnection between said handle and thesupport and switch elementsmounted on the support and operated by the handle.

In testimony whereof I hereto aiix my sig- I nature. y l

- 1 CLARENCE A. DE GIERS.

